1.5's or 1.6's?

Hey Guys, Here's my dilemma. I think I may have gotten too big a cam for my car and I'm thinking I've screwed up enough that I have a very narrow powerband.
The problem I'm getting is I get gobs of torque in 2nd gear up to red line but once I shift into 3rd, I'm chugging along and my engine isn't building up enough speed to keep the supercharger at 7lbs boost (more like 3 or 4).
I've got an SLP cam in it. Here are the specs:
SLP 51002 duration, 1.5 lift, 1.6 lift, Lobe sep. 206/214 .470/.490 .501/.522 112deg
I know it's not a supercharger cam which I should have gotten but I put the supercharger in after the cam so by then it was too late. Anyhow, it's a 1989 305, TPI with a bunch of mods, siamesed runners, intake and plenum siamesed and ported. 52mm throttle body. ATI procharger (max 7lbs)
My question is this: I'm thinking I might be getting some valve float. Will going back to 1.5 ratio rockers be of any benefit. In my head, it seems that if there's less lift, there should be a less chance that valve float would occur. Is this sound reasoning? I'm currently using 1.6 roller rockers on the intake side and 1.5 stock rockers on the exhaust. I would have used 1.6's on the exhaust side but I don't have enough valve clearance and I didn't have 1.5 roller rockers to put in at the time (I do now). So what is your recommendation? Switch all the rockers over to 1.5 roller's or keep the 1.6's on the intake and put 1.5 rollers on the exhaust?
Thanks.
-Bruce
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That cam you are using is a baby sized cam. It does have too much overlap for a supercharger. The real problem is you wasted all that money on a 305. If your in the 13's with that set up i would be shocked. I think you should have used the 1.6's on the exhaust side as the exhaust side flows less air out. Anyway use 1.5's all around. and shift the car at 6000 rpm at least. By the way what kind of heads are you using and what is the rear end gear ratio? All aboard the Yankee express, next stop October.....
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for a

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I know it isn't a 350 or a 383 or a 400 but that's what I chose to do. It's kinda like me saying you're wasting money because you're using AOL. That's what you choose to do. I Really wanted to go to a 350 but I didn't because I was out of work at the time and didn't have the money to drop into getting a 350 and the associated parts. I know it probably wouldn't have cost me more than $1000 but that's $1000 more than I had at the time.
The heads are stock heads, ported and polished by myself. I didn't get them flowed though I probably should have.
Like I said in my original post, if I had used 1.6's on the exhaust side, I'd now have a crappy running 305 because the exhaust valves would be bent. I can't use 1.6's on the exhaust side. Rearend is 3.23's
TPI's can't get up to 6000 rpm, the stock TPI dies out at 4500 and I'd be surprised if mine revs any higher.
Any reason you recommend me using 1.5's all around instead of keeping 1.6's on the intake? I guess I'm more interested in the reasoning rather than just the suggestion.
Thanks for the reply,
-Bruce
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First sorry its taken me so long to respond, i have been busy at work. Stock TPI can "make" it to 6000, i routinely shift my iroc at 6250 the redline on my cam. True it doesn't make as much HP as other intakes it doesn't mean you should kill your powerband totally. If your shifting that 305 at 4500 rpm two things are happening. 1. when you enter the next gear the car is out of its powerband, the higher rpm you shift at the higher rpm you will start the next gear at, 2 the supercharger needs rpm to make maximum boost, not as much as a turbo relies on it but at idle and low rpm your not pumping 10 lbs of boost, follow me so far? I recommended the 1.5's because your heads need help on the exhaust side. If you add extra air on the intake side with out compensating on the exhaust side you create a bottle neck. More air in means you need to get more air out. Its kinda like a bath tub, if water is filling up faster then the drain can handle it starts to back up. just my thinking into the situation
All aboard the Yankee express, next stop October.....
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1.6's
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Thanks for the help guys,
I'm definitely getting valve float if TPI's can make it past 4500. After about 4500, I'm getting no power, just a lot of noise. Sounds like it's time to change my valve springs to a higher spring rate.
Now my biggest concern is that I won't be able to find a stock diameter valve springs with a higher spring ratio but I guess a little research will give me an idea of what will fit and what won't. It looks like I'll need something with an installed spring rate of about 100# and a max rate of about 300+# compressed. Does that sound about right?
I'll also swap back to 1.5 rockers since they're less likely to give me valve float and I won't have any clearance issues.
Thanks again and if any of you think of anything else, please let me know.
-Bruce
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and
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You didn't mention how it leaves the line. If your bogging in first, you need a higher stall speed torque converter.
What your exhaust system size? What valve springs are you running? what lifters? Have you had your EC's Prom either replaced or recalibrated?
Since your getting thru second gear alright, I would not blaime the rear gear ratio. Charles
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line
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I'm good off the line, it's not great but it's not bad. I moved to a 1800 stall converter when I rebuilt the tranny, it's not much better but I believe the stocker was 1500 or less.
The exhaust is stock from the cat back to the muffler. I've got Edelbrock 1 5/8ths headers to the cat at 3 inches. Intermediate pipe is 2.5 to a flowmaster crossflow muffler.
Valve springs are a stock spring replacement and lifters are also stock hydraulic rollers.
I have an accel DFI programmable ECU that I'm fixin' to put in within the next couple weeks. I would hope that will help everything at once. Mostly looking at a little more power and better gas mileage. I think my ignition timing might be a little conservative because I'm worried about detonation. I'm also wondering if moving to an extended reach spark plug would help.
I hope that information helps. Thanks.
-Bruce
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Stock replacement valve springs are not going to let you rev. If you want to turn more then 5,500 say 6,000, or your getting valve float, you need stronger springs. A good set should not cost more then $150.
The reason I asked about a the E-prom is your spark and fuel maps are totally wrong for the blower. You should install the DFI controller and make a few runs, making adjustments as needed.
You might also try uncorking the after cat pipe, for a run or two. The 2.5 mid pipe may be a source of restriction. Your pumping a lot of air in with the blower.
Charles
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If he is shifting at 4500 rpm third gear in a 700r is 1:1, thats where gear can help you as well. 1:1 isn't exactly a acceleration ratio with 3.23 rear gear, maybe with 3.73 or 4.11 you would already make enough rpm in third gear to make enough hp/torque to carry you on All aboard the Yankee express, next stop October.....
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